<template>
	<view>
    <!-- 自定义的搜索组件 -->
    <my-search @click="gotoSearch"></my-search>
    
		<view class="scroll-view-container">
      <!-- 左侧滚动区域 -->
		  <scroll-view
        class="left-scroll-view"
        scroll-y="true"
        :style="{height: wh + 'px'}"
      >
        <view
          :class="{'left-scroll-view-item': true, 'active': index === active}"
          v-for="(item, index) in cateList"
          :key="index"
          @click="activeChanged(index)"
        >{{item.cat_name}}</view>
		  </scroll-view>
      
      <!-- 右侧滚动区域 -->
      <scroll-view
        class="right-scroll-view"
        scroll-y="true"
        :style="{height: wh + 'px'}"
        :scroll-top="scrollTop"
      >
		    <view
          class="cate-lv2-item"
          v-for="(item2, index2) in cateLevelTwo"
          :key="index2"
        >
          <view class="cate-lv2-item-title">
            {{item2.cat_name}}
          </view>
          <!-- 动态渲染三级分类 -->
          <view class="cate-lv3-box">
            <!-- 三级分类item -->
            <view
              class="cate-lv3-item"
              v-for="(item3, index3) in item2.children"
              :key="index3"
              @click="gotoGoodsList(item3)"
            >
              <!-- 图片 -->
              <image :src="item3.cat_icon" mode=""></image>
              <!-- 为本 -->
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
		  </scroll-view>
		</view>
	</view>
</template>

<script>
	export default {
		data() {
			return {
        // 窗口的可用高度 屏高 - navgationBar高度 - tabbar高度
				wh: 0,
        // 分类数据列表
        cateList: [],
        active: 0,
        // 二级分类列表
        cateLevelTwo: [],
        // 滚动条距离顶部的距离
        scrollTop: 0,
			}
		},
    onLoad() {
      // 获取当前系统的信息
      const sysInfo = uni.getSystemInfoSync()
      // 为wh窗口可用高度动态赋值
      this.wh = sysInfo.windowHeight - 50
      this.getCateList()
    },
    methods: {
      // 获取分类列表信息
      async getCateList() {
        const { data: res } = await uni.$http.get('/api/public/v1/categories')
        if (res.meta.status !== 200) return uni.$showMsg()
        this.cateList = res.message
        // 为二级分类列表赋值
        this.cateLevelTwo = res.message[0].children
      },
      // 改变左侧列表项
      activeChanged(index) {
        this.active = index
        this.cateLevelTwo = this.cateList[index].children
        this.scrollTop = this.scrollTop === 0 || 0
      },
      // 三级分类列表项的点击
      gotoGoodsList (item) {
        uni.navigateTo({
          url: `/subpkg/goods_list/goods_list?cid=${item.cat_id}`
        })
      },
      // 点击前往搜索页面
      gotoSearch() {
        console.log(11);
        uni.navigateTo({
          url: '/subpkg/search/search'
        })
      }
    }
	}
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;
  .left-scroll-view {
    width: 120px;
    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;
      // 激活项的样式
      &.active {
        background-color: #FFFFFF;
        position: relative;
        
        // 渲染激活项左侧的红儿指示边线
        &::before {
          content: '';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
  .cate-lv2-item-title {
    font-size: 12px;
    font-weight: bold;
    text-align: center;
    padding: 15px 0;
  }
  .cate-lv3-box {
    display: flex;
    flex-wrap: wrap;
    .cate-lv3-item {
      width: 33.33%;
      margin-bottom: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      image {
        width: 60px;
        height: 60px;
      }
      text {
        font-size: 12px;
      }
    }
  }
}
</style>